Earlier this month, a friend of Klum's told PEOPLE that the relationship between the model-turned-mogul and Kirsten is "complicated" but that Kirsten is Klum's "no. 1 confidante."

While their relationship is yet to be publicly confirmed, during a recent appearance on Katie, Klum spoke fondly of Kirsten, explaining that he has "cared for our four children and helped us tremendously" since working for her over the past four years.
– Jennifer Garcia